Bactericidal Effect of Selenium Nanoparticles Combined with Povidone-iodine on Pathogenic Bacteria in Surgical Site Infection / 中山大学学报(医学科学版)

ObjectiveTo investigate the bactericidal effect of loaded multifunctional povidoneiodine-nanometer selenium （PVP-I@Se） disinfectant on Staphylococcus aureus （SA） and methicillin-resistant Staphylococcus aureus （MRSA）， and to provide an experimental basis for the reduction of surgical site infection （SSI）. MethodsThe control group was the povidone iodine （PVP-I） group with different concentrations of iodine （50， 75， 100， 200 and 400 μg/mL）. The PVP-I@Se group （experimental group） was the PVP-I group further supplemented with 2 μg/mL Selenium nanoparticles （SeNPs）. Then we compared the bactericidal effect of the two groups of disinfectant solutions on SA and MRSA by examining the minimum inhibitory concentration （MIC）， minimum bactericidal concentration （MBC）， the shortest sterilization time at a concentration of 50 μg/mL iodine and the inhibition zone diameters at concentrations of 200 μg/mL and 400 μg/mL iodine. ResultsMIC values of PVP-I against SA and MRSA were both 79.17 μg/mL， and those of PVP-I@Se were 54.17 and 70.83 μg/mL， respectively. MBC values of PVP-I against SA and MRSA were 129.17 and 150.00 μg/mL， respectively， and those of PVP-I@Se were 70.83 and 87.50 μg/mL， respectively. At a concentration of 50 μg/mL iodine， the shortest sterilization time of PVP-I for SA and MRSA was 130 s and 140 s， respectively， and that of PVP-I@Se was 65 s and 75 s， respectively. At a concentration of 200 μg/ml iodine， the inhibition zone diameters of PVP-I for SA and MRSA were 7.67 mm and 8.33 mm， and those of PVP-I@Se were both 9.50 mm. At a concentration of 400 μg/mL iodine， the inhibition zone diameters of PVP-I for SA and MRSA were 9.00 mm and 9.33 mm， and those of PVP-I@Se were 11.67 mm and 12.00 mm， respectively. ConclusionsPVP-I with different concentrations of 50， 75， 100， 200 and 400 μg/mL iodine supplemented with 2 μg/mL SeNPs have better and faster bactericidal effect on SA and MRSA. When combined with SeNPs， PVP-I can enhance the bactericidal activity against SA and MRSA， but with better sensitizing effect on SA than MRSA and higher demand of iodine concentration （400 μg/mL） for sensitizing effect on MRSA. This study provides a theoretical basis for selecting optimal concentration and action time of the disinfectant， thus reducing SSI.

Actividad bactericida de anticuerpos anti-ABO en colonias aisladas de Escherichia coli

Se ha estudiado la interacción entre antígenos ABO y microorganismos, incluidos los presentes en la microbiota, sobre la posible acción de antígenos y anticuerpos ABO en la susceptibilidad a enfermedades infecciosas. El objetivo de esta investigación fue determinar el título mínimo de la bacteria Escherichia coli capaz de sufrir la acción bactericida in vitro de los anticuerpos humanos anti-ABO. La selección de las muestras de sangre utilizadas se realizó mediante la aplicación de un cuestionario, fenotipado sanguíneo (un voluntario de cada fenotipo ABO) y la titulación de anticuerpos ABO. Se preparó una suspensión bacteriana (inoculo) y se agregó al suero de los voluntarios, seguido de la inoculación en Mueller Hinton Agar, luego de 24 horas, los resultados se leyeron e interpretaron con análisis por duplicado. No hubo diferencia significativa en la Prueba Bactericida entre las pruebas 1 y 2 en los grupos sanguíneos A, B, AB, O y Control Positivo. Hubo una diferencia significativa en el suero humano puro cuando se analizó el Grupo A x Control Positivo; Grupo B x Control Positivo; Grupo AB x Control Positivo y Grupo O x Control Positivo. No hubo diferencia significativa en las otras diluciones. Se concluye que los anticuerpos anti-ABO tienen efecto bactericida cuando existe una alta concentración de bacterias en el ambiente.

The interaction between ABO antigens and microorganisms, including those present in the microbiota, has been studied about the possible action of antigens and ABO antibodies in susceptibility to infectious diseases. This research aimed to determine the minimum titer of the Escherichia coli bacteria capable of undergoing in vitro bactericidal action of human anti-ABO antibodies. The selection of blood samples was performed through a questionnaire, blood phenotyping (one volunteer of each ABO phenotype), and the titration of ABO antibodies. A bacterial suspension (inoculum) was prepared and added to the serum of the volunteers, followed by inoculation in Mueller Hinton Agar. After 24 hours, the results were read and interpreted with duplicate analysis. There was no significant difference in the bactericidal test between tests 1 and 2 in blood groups A, B, AB, O, and Positive Control. There was a significant difference in pure human serum when Group A x Positive Control was analyzed, Group B x Positive Control, Group AB x Positive Control, and Group O x Positive Control. There was no significant difference in the other dilutions. It is concluded that anti-ABO antibodies have a bactericidal effect when there is a high concentration of bacteria in the environment.

Antibacterial activity of coffee extract against common human bacterial pathogens in a teaching hospital of semi urban setup

Background: Coffee has a stimulant nature for which it is consumed worldwide, especially in Indian subcontinent. It also contains various antioxidant and antibacterial properties and is good for health. Aims and Objectives: This study done in tertiary care teaching hospital, aims to assess the antibacterial activity of coffee extract in surgical wound infections. Materials and Methods: The antibacterial activity of coffee extract against pathogenic bacteria (Gram-positive and Gram-negative) isolated from the surgical wounds was tested. Results: Both Gram-positive and Gram-negative bacteria were found sensitive to the methanol coffee extract. Conclusion: Our study revealed that coffee extract can be used in the future as a substitute antimicrobial for the treatment of pathogenic bacteria due to its wide antimicrobial activity and we suggest advanced study on coffee extract to explore the bioactive compounds accountable for the detected antimicrobial activity.

Bactericidal permeability increasing protein-anti-neutrophil cytoplasmic antibody- associated vasculitis complicated with bronchiectasis: a case report and literature review / 中华肾脏病杂志

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of systemic small vasculitis characterized by the detection of ANCA in serum. Bactericidal permeability enhancing protein (BPI) is one of the target antigens of ANCA. BPI-ANCA-associated vasculitis is not common clinically, and the combination of bronchiectasis is not accidental. The paper reported a case of BPI-ANCA-associated vasculitis with renal damage combined with bronchiectasis. We reviewed relevant literature to explore the characteristics of BPI-ANCA-associated vasculitis and the correlation between bronchiectasis and ANCA-associated vasculitis, so as to improve the clinician's understanding on this disease.

Isolation, Identification and Mode of action of Partially Purified Bacteriocins from Lactic Acid Bacteria in Fermented Cassava Grits

The study on the isolation, identification and mode of action of partially purified bacteriocin from lactic acid bacteria found in fermented cassava grits was carried out. Fermented cassava grits were collected from different garri processing plants and transported with cold box to the laboratory for analysis. The viable microbial count after the partially purified bacteriocin from the various lactic acid bacteria isolates were grown against the food borne bacteria (Staphylococcus aureus and Bacillus subtilis) ranged from 0.98 x 103 CFU/ml for partially purified bacteriocin from isolate 6 at 8 hrs to 9.2 x103 CFU/ml for isolate 3 at 24 hrs. Similar results were obtained against Bacillus subtilis with microbial counts that ranged from 1.02 x102 CFU/ml for isolate 3 at 8 hrs to 9.2 x 102 CFU/ml at 24 hrs. Isolates 6, 7, 10 and 11 were bactericidal to both Staphylococcus aureus and Bacillus subtilis while isolate 3 was bacteriostatic. The viable microbial count after the partially purified bacteriocin was grown against the foodborne bacteria (Escherichia coli and Salmonella typhi) ranged from 1.0 x102 CFU/ml for partially purified bacteriocin from isolate 3 at 8 hrs to 7.1 x 102 CFU/ml for partially purified bacteriocin from isolate 6 at 24 hours. The microbial count against Salmonella typhi ranged from 6.50 x 102 CFU/ml for isolate 6 at 8 hrs to 8.5 x 102 CFU/ml for isolate 7 at 24 hrs. Partially purified bacteriocins from isolates 3 and 7 were bacteriostatic while isolates 6, 10 and 11 were bactericidal to Escherichia coli and Salmonella typhi. This result showed that the partially purified bacteriocins were very efficacious in killing or inhibiting the growth of some foodborne pathogens which can be applied in biopreservation.

Research progress on the application of photodynamic therapy in periodontal treatment / 口腔疾病防治

@#Periodontitis is a chronic inflammatory disease that is initiated by bacteria. Pathogens and their virulence factors alter normal cellular metabolic activity and deteriorate periodontal microconditions. Owing to the complexity of tooth structure and the limitation of conventional treatment, we may not live up to all patients’ expectations, especially those with grade C and stage Ⅲ or Ⅳ periodontitis. With the advantages of bactericidal effects, high safety, inhibition of bacterial drug resistance and promotion of tissue healing, photodynamic therapy （PDT） seems to be an ideal technology in periodontal treatment. However, it cannot remove subgingival stones and still cannot replace mechanical treatment to preliminarily control periodontal inflammation. Therefore, near-infrared low-energy light combined with traditional photosensitizers is mostly used in clinical periodontal adjuvant treatment. In periodontal maintenance treatment on a regular basis, a single application can also reduce the sensitivity of patients and effectively control plaque, but its effect will be affected by the degree of periodontal inflammation, the concentration and type of photosensitizer, the energy of the light source, etc. With the further development of material science, the performance of photosensitizers to accelerate oxides and target bacteria will be optimized. In the future, parameters of PDT need to be designed in large-scale studies in accord with different stages and grades of periodontitis.

Screening of new virulence genes of high virulence Klebsiella pneumoniae by Tn-seq / 中华微生物学和免疫学杂志

Objective:To construct a transposon mutation library and screen new virulence genes of hypervirulent Klebsiella pneumoniae(hvKp). Methods:The transposon mutation library was constructed and treated with human serum. The changes in the abundance of the genes of library mutant strains were analyzed by Transposon sequencing (Tn-seq). Besides, KEGG (kyoto encyclopedia of genes and genomes) annotation and enrichment analysis were performed on the screened genes.Results:A total of 405 genes were screened out according to the abundance of the genes in the library treated with human serum was 20% lower than that without treated, and 351 genes, 86.7% of these genes were conserved in HS11286, NJST258_1, NTUH-K2044 and RJF293. Ten genes existed in strains NTUH-K2044 and RJF293 with high virulence, while these genes were absent in HS11286 and NJST258_1 with low virulence. The mutants with genes such as glycosyl transferase gene wzy, aggregator protein gene wzi and capsule transporter gene wza, which belong to the capsule polysaccharide gene clusters, could not be detected after serum treatment. The abundance of iron carriers gene clusters such as aerobacterin and salmonellin in each library changed less than one time. KEGG annotation results showed that most annotated genes were involved in amino acid metabolism, cofactor and vitamin metabolism, carbohydrate metabolism, etc. Conclusions:Tn-seq is a reliable method to screen functional genes. In this study, 405 candidate virulence genes of hvKp were successfully screened out, providing an experimental basis for further research on the function and regulation mechanism of new virulence genes of hvKp.

Association between circulating exhausted CD4+ T cells with poor meningococcal C conjugate vaccine antibody response in HIV-infected children and adolescents

OBJECTIVES: To investigate the expression levels of surface markers of activation (CD38 and HLA-DR), inhibition (PD-1, TIGIT and CD57) and co-stimulation (CD28 and CD127) on CD4+ T cells of children/adolescents with vertical HIV infection (HI patients) and HIV-uninfected (HU) controls vaccinated with the meningococcal C conjugate vaccine (MCC). METHODS: HI patients (n=12), aged 8-17 years, were immunized with two MCC injections, while HU controls (n=9), aged 5.3-10.7 years, received a single MCC dose (as per national recommendation at the time of this study, a single MCC vaccine dose should be given for healthy children and youth aged 1-18 years). The HI patients were categorized according to the combined antiretroviral therapy (cART) treatment. Blood samples were obtained before vaccination, after priming, and after the administration of a booster dose of vaccine to determine the serum bactericidal antibody (SBA) titers and the expression levels of surface markers on CD4+ T cells by flow cytometry. The levels of serum cytokines, IL-4 and CXCL-13 were also measured using Luminex kits. RESULTS: The co-expression of the TIGIT-HLA-DR-CD38 molecules increased in the CD4+ T cells of HI patients/no-cART who also showed a lower frequency of CD127+CD28+ CD4+ T cells than HI patients/cART and HU group subjects. There were significant negative correlations between the frequency of exhausted CD4+ T cells and the SBA response. IL-4 levels were higher in HI patients/cART and positively correlated with SBA titers but negatively associated with the expression of exhaustion markers. Moreover, the CXCL-13 levels were positively correlated with the exhausted CD4+ T cells. CONCLUSION: The results of our study suggest that the co-expression of exhaustion markers and/or loss of co-stimulatory molecules influence the SBA response in HI patients.

Antibacterial and Antibiofilm Activities of Crude Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 against Foodborne Bacterium, Yersinia enterocolitica

The antibacterial and antibiofilm activities of crude extract of Lasiodiplodia pseudotheobromaeIBRL OS-64 was studied and tested against a foodborne pathogenic bacterium, Yersinia enterocolitica. The ethylacetate extract exhibited favorable antibacterial activity with the zone of inhibition was 20.3±0.6 mm compared to dichloromethane (15.0±0.3 mm) and butanol (9.0±0.3 mm) extracts. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of the extract were 125 and 250 μg/mL, respectively. Structural degeneration studies through scanning electron microscopy (SEM) and transmission electron microscope (TEM) micrographs exhibited major abnormalities that occurred on thebacterial cells after exposureto the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The findings showed that the extract possesses antibiofilm activity against the initial and preformed biofilm of Y. enterocoliticawith the highest inhibition value of 69.12% and 58.70%, respectively The results also revealed the initial biofilm was more susceptible to the extract as compared to pre-formed biofilm. The light microscopy (LM) and SEM photomicrographs proved that thefungal extract significantly eliminates extracellular polysaccharide (EPS) matrices and hinder the attachment of the bacterial cells for biofilm formation. Therefore, the current study suggested the ethyl acetate crude extract from an endophytic fungus, L. pseudotheobromae IBRL OS-64 may be an effective antibacterial and anti-biofilm agent to treat foodborne pathogens

Chemical characterization, antimicrobial and antioxidant activity of sugar-apple (Annona squamosa L. ) pulp extract / Caracterización química, actividad antimicrobiana y antioxidante del extracto de pulpa de manzana de azúcar (Annona squamosa L. )

Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.

Los conservantes sintéticos están ampliamente presentes en los alimentos procesados, pero la mayoría tienen potencial carcinogénico, lo que requiere el desarrollo de nuevas alternativas naturales para el control microbiano, como los extractos de frutas. El objetivo del estudio fue evaluar la caracterización química, la actividad antioxidante y antimicrobiana de la pulpa de manzana de azúcar (Annona squamosa L.). Se evaluaron las características fisicoquímicas, y se evaluó su actividad antioxidante mediante el método DPPH y antimicrobiano por difusión en disco, concentración inhibitoria mínima y concentración bactericida mínima contra cepas de Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes y Staphylococcus aureus. El análisis fisicoquímico reveló que la pulpa de manzana de azúcar tiene 75.0% de humedad, 3.0% de cenizas, 4.0% de proteínas, 0.2% de lípidos, 3.3% de fibras y 14.5% de carbohidratos. La actividad antioxidante del extracto por el método DPPH fue del 20.6%. El extracto de pulpa de la manzana de azúcar tenía zona de inhibición para Staphylococcus aureus, efecto inhibidor satisfactorio contra Staphylococcus aureus, Escherichia coli, Listeria monocytogenes y Salmonella Typhimurium, pero no presenta efecto bactericida. La pulpa de manzana de azúcar presenta niveles adecuados de nutrientes y potencial para la aplicación de alimentos debido a su actividad microbiológica y propiedades antioxidantes.

Antibacterial efficacy of black seed honey in combination with penicillin and amoxiclav against gram-positive bacteria

Background:The emergence of antimicrobial resistance possessesa great threat for the existence of mankind. Antibiotics like penicillin and amoxiclav are at the brink of losing their efficacy entirely in exposure to resistant bacteria. Thus, the present study was aimed to find out the antibacterial efficacy of black seed honey as an alternative natural source which can act independently and boost the efficacy of standard drugs alongside. Methods:Penicillin, amoxiclav and black seed honey were first individually trailedagainst four gram-positive bacteria -Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis andMicrococcus luteus.Afterwards, penicillin and amoxiclav were used in combination with honey and compared the synergistic effects with their individual efficacy. Zones of inhibition from well diffusion method, percentage inhibition, minimum inhibitory and bactericidal concentrations by microdilution method were determined in the present study.Results:Black seed honey alone demonstrated great inhibitory potential against S. aureus (9.7 mm), S. epidermidis (9.9 mm) and M. luteus(9.3 mm) in well diffusion method. Moreover, its combination with amoxiclav showed synergistic effect against all bacteria except S. epidermidis. However, its conjugation with penicillin was not able to produce any synergism as exhibited by zones of inhibition. The lowest concentration (1.56%) of honey applied individually or in combination in microdilution method foundhighly effective which established an inverse dose dependent relationship with efficacy.Conclusions:From the data it can be concluded that the black seed honey is a highly potent natural agent which can be utilized in antimicrobial therapy. However, further investigation is recommended to identify the responsible compound for such activity.

Efficacy of Consumer Antibacterial and Non-antibacterial Body Washes on Skin Normal Flora and Pathogen

@#Introduction: Antibacterial products contain active ingredients that are used to prevent bacterial growth and contamination. Previous studies suggest that antibacterial products are no more effective at removing s kin pathogen compared to plain soap. It is essential to collect the data regarding the effectiveness of antibacterial products with the purpose of continuous surveillance in the detection of emerging resistance pattern. Method: In vitro antimicrobial activity of six products were established on four species of bacteria namely Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa that represent the bacterial pathogen commonly found on human skin and the surrounding environment. These pathogens are also implicated as the causative organisms for skin infections. Results: Product that contains triclosan has the highest bactericidal effect as it is effective against a broad spectrum of bacteria. Body washes without any antibacterial agent also exhibit bactericidal activity but at higher concentrations. Gram-positive bacteria showed more sensitivity compared to gram-negative bacteria. Conclusion: Antibacterial and non-antibacterial products have bactericidal effects at different concentration. Different active ingredients showed different antibacterial effects on tested bacteria. Extend usage of antibacterial products pose adverse effects on skin normal flora and can lead to antimicrobial resistance.

Autophagy in neutrophils

Autophagy is a highly conserved intracellular degradation and energy-recycling mechanism that contributes to the maintenance of cellular homeostasis. Extensive researches over the past decades have defined the role of autophagy innate immune cells. In this review, we describe the current state of knowledge regarding the role of autophagy in neutrophil biology and a picture of molecular mechanism underlying autophagy in neutrophils. Neutrophils are professional phagocytes that comprise the first line of defense against pathogen. Autophagy machineries are highly conserved in neutrophils. Autophagy is not only involved in generalized function of neutrophils such as differentiation in bone marrow but also plays crucial role effector functions of neutrophils such as granule formation, degranulation, neutrophil extracellular traps release, cytokine production, bactericidal activity and controlling inflammation. This review outlines the current understanding of autophagy in neutrophils and provides insight towards identification of novel therapeutics targeting autophagy in neutrophils.

Time-kill study and morphological changes of Proteus mirabilis cells exposed to ethyl acetate crude extract of Lasiodiplodia pseudotheobromae IBRL OS-64

@#Aims: To investigate time-kill curve and morphological changes of Proteus mirabilis cells exposed to ethyl acetate crude extract of endophytic fungus, Lasiodiplodia pseudotheobromae IBRL OS-64, isolated from Ocimum sanctum. Methodology and results: Inhibitory effect of the fungal extract against the test bacteria via disc diffusion assay showed a fair antibacterial activity with diameter of inhibition zone was 12.0 ± 0.4 mm. The Minimal Inhibition Concentration (MIC) and Minimal Bactericidal Concentration (MBC) values of the ethyl acetate extract against P. mirabilis was 250 and 500 µg/mL, respectively. The value of MBC which is two-fold higher than MIC value indicated that the fungal extract exerted bactericidal effect on bacterial cells of P. mirabilis. Time-kill curve study revealed that the bactericidal effect of the crude extract towards test bacteria was both dose and time dependent. Scanning electron microscope (SEM) observation revealed that the bacterial cells of P. mirabilis exposed to fungal crude extract resulted in formation of pits, irregular shape of the bacterial cell and ultimately cell death beyond repair. Conclusion, significance and impact of the study: The time-kill curve study, and cell morphological changes suggested the potential of ethyl acetate extract of L. pseudotheobromae IBRL OS-64 against P. mirabilis infection by formation of cavities, irregular bacterial cell that leads to ultimate cell death and the extract may have pharmaceutical potential to be develop as antibacterial agent.

In vitro growth inhibition and bactericidal activity of spathulenol against drug-resistant clinical isolates of Mycobacterium tuberculosis

ABSTRACT Spathulenol was isolated from an extract of Azorella compacta Phil., Apiaceae, by various chromatographic method; identification of the chemical structure was confirmed by comparing its spectroscopic data with those reported in the literature. The anti-Mycobacterium tuberculosis activity of spathulenol was evaluated on MDR, pre-XDR, and XDR clinical isolates of M. tuberculosis, as well as on the reference susceptible strain H37Rv and its cytotoxic activity was evaluated on the Vero Cell Line. The anti-M. tuberculosis activity of spathulenol was twice as potent against the MDR, pre-XDR, and XDR clinical isolates (6.25 µg/ml) than on the susceptible H37Rv strain (12.5 µg/ml). Additionally, the anti-M. tuberculosis activity shown by spathulenol was established as bactericidal on drug-resistant and susceptible strains of M. tuberculosis. Finally, cytotoxic activity on the Vero cell line (CC50 = 95.7 µg/ml) indicated that spathulenol is a selective anti-M. tuberculosis compound, with a selective index of 15.31 against drug-resistant clinical isolates of M. tuberculosis.

Development of a new Colombian product, effective for the treatment of carious lesions: a case study / Desarrollo de un nuevo producto colombiano, efectivo para el tratamiento de las lesiones cariosas: un caso de estudio

SUMMARY Purpose: We present a new Colombian product researched and developed by Seven Scientific Foundation, which has been very useful for the removal of the carious tissue in patients who have used this innovative product. Methods: We used a chemical-mechanical removal of dental caries. This product is made with 10% papain which is the active principle and works as a debriding agent, as well as being a bacteriostatic, bactericidal and anti-inflammatory agent; and also contain dragon's blood (Croton lechleri) sap which is an effective as analgesic/anti-inflammatory and especially as a healing agent. In this article, we present a case study of a patient, whose dental carious tissue was removed, using the dental new product. Description of the case report: In this article, we present a case study of a patient, whose dental carious tissue has been removed, using the new dental product, therefore this innovative technique of removal of the atraumatic carious tissue. Conclusions: This method is useful as it is a minimally invasive technique, without requiring the use of local anesthesia, or the additional use of dental instruments. It is used in the Colombian population of all ages and does not generate side effects in people who have used it so far.

RESUMEN Propósito: se investigó y desarrolló un nuevo producto dental el cual ha sido muy útil para la remoción del tejido carioso en los pacientes colombianos que han utilizado este innovador producto para la remoción químico-mecánica de las caries dentales. Métodos: Este producto está hecho a base de papaína al 10 % el cual es el principio activo y funciona como un agente debridante lo cual cicatriza el tejido removido, además de ser un agente bacteriostático, bactericida y antiinflamatorio. Descripción de reporte de caso: en este artículo se presenta un estudio de caso de un paciente al cual se le removió el tejido carioso dental. Conclusiones: Por lo tanto, esta técnica innovadora de remoción del tejido carioso atraumático resulta útil por ser una técnica mínimamente invasiva, sin requerir el uso de anestesia local al tejido afectado ni el uso adicional de instrumentos dentales. Se utiliza en la población colombiana de todas las edades y no genera efectos colaterales en las personas que lo han utilizado hasta el momento.

Effect of different methods of pasteurization on bactericidal action of human milk: A prospective observational study

Background & objectives: Pasteurization involves not only inactivation of pathogens, but also loss of immunological functions and bactericidal action of human milk. Hence, this study was aimed to explore the stability of such bactericidal action after subjecting human milk samples to thermal pasteurization under different condition of time and temperature. Methods: In this observational study 48 human milk samples were analyzed over a period of three months. The effect of holder and flash methods of pasteurization on bactericidal action against Escherichia coli was evaluated compared to the control sample before and after 72 h of storage at ?18癈. Results: Both holder and flash methods of pasteurization showed significant reduction in the E. coli growth to 46.4 and 25.5 per cent, respectively, after 24 h of incubation (P <0.001). The bactericidal activity was significantly more in samples subjected to holder method compared to flash method before and after 72 h of storage (46.41�.38 vs. 25.50�.74, P <0.001 and 42.27�.38 vs. 18.33�.55, P <0.001). Interpretation & conclusions: Our results showed that the bactericidal activity of human milk was better preserved by the holder method of pasteurization. Further well-powered and well-designed randomized trials are needed to confirm the findings.

Preparation, Characterization Of Silver-Nanoparticles From Seed Coat Exudates Of Celastrus Paniculatus Willd. And Their Bactericidal And Biofilm Inhibition Effects

We are reporting a novel approach for preparing silver nanoparticles with seed coat exudates of Celastrus paniculatus Willd, a medicinal plant traditionally used for the treatment of skin diseases, fever, leprosy and neurological disorders. HPTLC study revealed that aqueous, soluble seed coat exudates contain phenolics, alakaloids and flavonoids. The formation, crystalline nature and morphology of the nanoparticles were identified by UV–Vis spectroscopy, X-ray Diffraction (XRD) analysis, Transmission Electron Microscopy (TEM) and selected-area electron diffraction (SAED). Functional group stretching of aqueous soluble extracts was identified by using FTIR. Results revealed that nanosilver particles are spherical, range in size from 10 to 82 nm and crystalize in face-centered cubic structures. Surface-enhanced Raman spectra analysis showed that AgNP are capped with bioactive molecules from exudates and that they may act as precursors of the reduction of silver nitrate from the metallic state (Ag+) to the atomic state (Ag0). We also examined the minimal inhibitory concentration for bacteria Escherichia coli and Bacillus subtilis using a resazurin color assay. Nanosilver strongly inhibited the bacterial growth, leading to MIC values of 40µg/ml and 60µg/ml for the bacteria, respectively. The colony screening method and inhibition kinetics of biofilm formation in the Klebsiella pneumoniae strain were also studied using the tube method and a quantitative microplate assay. SEM analysis and quantification of the EPS revealed a fivefold decrease in concentration in treated compared to untreated. The inhibition response was duly reflected in SEM images.

Antibacterial Activity of Locally Prepared Herbal Cough Extracts against Klebsiella pneumoniae and Streptococcus pneumoniae

Aim: Cough due to Klebsiella pneumoniae andStreptococcus pneumoniae is currently managed by conventional antibiotics and herbal extracts in Uganda. However, much as these herbal extracts are extensively used, their antibacterial activity is not known. This study aimed at determining the antibacterial activity of the selected locally prepared herbal cough extracts against two bacterial strains i.e. Klebsiella pneumoniae (ATCC 700603), and Streptococcus pneumoniae (ATCC 49619). Methods: The herbal cough extracts were screened for antibacterial activity using Agar-well diffusion method for determining zone of inhibition, macro broth dilution method for Minimum Inhibitory Concentration (MIC) determination and Streak plate method for Minimum Bactericidal Concentration (MBC). Results:In vitro evaluation of antibacterial activity of the 5 brands of herbal cough extracts against K. pneumoniae and S. pneumoniae revealed that all extracts possessed significant antimicrobial effects against all microorganisms tested (p < 0.05). However, MM04 (35.6±0.0) mm and MM03 (33.6±1.5) mm had maximum zones of inhibition as compared to other herbal extracts against K. pneumoniae and S. pneumoniae respectively. Average MIC results for extracts against K. pneumoniae indicated that MM01 had the highest MIC (2.5000 mg/ml) while MM03 had the least MIC (0.0625 mg/ml). Average MIC results for extracts against S. pneumoniae showed MM01 had the highest MIC (2.0000 mg/ml) while MM03 3 had the least MIC (0.0438 mg/ml). Average MBC results for extracts against K. pneumoniae indicated that MM01 had the highest MBC (4.000 mg/ml) while MM03 had the least MBC (0.030 mg/ml). Average MBC results for extracts against S. pneumoniae showed MM01 had the highest MBC (4.000 mg/ml) while MM03 had the least MBC (0.033 mg/ml). Conclusion: The results obtained in present study were revealed that locally prepared herbal extracts had significant antibacterial activity. Hence they can be used as promising alternatives of antibiotics used against Respiratory Tract Infections due to K. pneumoniae and S. pneumoniae.

Time-kill assay and post-antibiotic effect of acetone extract from the stem bark of Canarium odontophyllum against Methicillin-resistant Staphylococcus aureus Mu50 strain

Canarium odontophyllum Miq. is an indigenous fruit found in Sarawak, Malaysia. Methicillin-resistant Staphylococcusaureus (MRSA) is a deadly pathogen that causes to hospital (health-care-acquired MRSA [HA-MRSA]) and community(CA-MRSA) infections worldwide. Vancomycin has been the therapeutic drug of choice against MRSA, but unfortunatelythis pathogen has developed some degree of resistance to vancomycin. This research aimed to evaluate the antimicrobialactivity of the stem bark extract of C. odontophyllum against MRSA Mu50 strain. The minimum inhibitory concentration(MIC) and minimum bactericidal concentration (MBC) of extract and vancomycin against MRSA were determined usingbroth microdilution method and streak plate method. The rate of killing by the extract against Mu50 strain was determinedusing time-kill assay (TKA) at ×1 MIC, ×2 MIC, ×4 MIC, and ×8 MIC of the extract. The post-antibiotic effect (PAE) timeof extract ×10 MIC against MRSA was also investigated. The extract exhibited bacteriostatic effect against MRSA Mu50strain with MIC and MBC values of 1.563 mg/ml and 3.125 mg/ml, respectively. From TKA analysis, the extract was notcapable of killing the Mu50 strain at ×1 MIC and ×2 MIC, but it displayed bactericidal activity at higher concentrationstested. Interestingly, the acetone stem bark extract of C. odontophyllum at ×4 MIC showed comparable time-killingkinetic with the standard antibiotic in the study. The PAE time of the extract was 3.6 ± 0.51 h against MRSA Mu50compared to vancomycin at 2.4 ± 0.68 h. In conclusion, the stem bark acetone extract from C. odontophyllum demonstratedconcentration-dependent bactericidal effect with prolonged PAE time against MRSA Mu50 strain.